#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>

using namespace std;

const int N = 1001;

int get_unique_count(int a[], int n)
{
    int cnt = 0;
    for (int i = 0; i < n; i++)
    {
        bool is_same = true;
        for (int j = 0; j < i; j++)
        {
            if (a[i] == a[j])
            {
                is_same = false;
                break;
            }
        }
        if (is_same) cnt++;
    }
    return cnt;
}

int main()
{
    int a[N], n;
    cin >> n;
    for (int i = 0; i < n; i++) cin >> a[i];
    cout << get_unique_count(a, n) << endl;
    return 0;
}

